Valve for carburetors



July 5, 1938. G. HAMMOND VALVE FOR4 CARBURETOR Filed Feb. 20, 1954 Patented July 5, 1938 UNITED STATES PATENT OFFICE VALVE Fon oARBURE'roRs Grant Hammond, Hamden, Conn.

Application February 20, 1934, Serial No. 712,106

2l Claims.

My invention relates to structures which are commonly employed for mixing hydrocarbon or similar fluids with air for combustion purposes, and an object of my invention, among others, is 5 the production of a device of this type which shall be Vsimple in construction and particularly eilicient as to the results obtained by its operation.

One form of a valve for carburetors embodying my invention and in the construction and use of which the objects herein set out, as well as others,may be attained is illustrated in the accompanying drawing in which- Figurel 1 is a side View o-f my improved carburetor.

Figure 2 is a View in central lengthwise section 'through `the same.

Figure 3 is an end View.

,A Figure 4 is a view in section on a plane denoted .by vthe dotted line 4-4 of Fig. 2.

AFigure 5 is a view in section on a plane denoted by the dotted line `5--5 of Fig. 2.

Figure 6 is an isometric View on an enlarged scale illustrating an improved valve forming a part of this carburetor.

Figure 'luis a'view in central lengthwise section through said valve.

Figure 8 is a view in lengthwise section through a connecting rod for operating a valve for choking purposes.

n Figure 9 is a detail sectional view illustrating the way of placing the vacuum cup guide support in position.

In the accompanying drawing the numeral I vdenotes the case vor shell of my improved carburetorwhich is generally of a shape round in cross- 4section and may be composed of any suitable material,y said case having an opening extending from end to end` therein with a mouth I I forming an air inlet at oneend and an opening I2 comprising an outlet at the opposite end. A supporting ring I3 is screw threadedly engaged with the air inlet end of the shell, as shown in Fig. 2 of the drawing, the edge of the opening through said ring forming a ange I4 overlapping the mouth I I of the opening into the shell. The body of the `case is reduced in diameter toward that end opposite fthe mouth, the opening along this reduced portion being of cylindrical shape forming a mixing chamber I which is gradually enlarged merging into an air inlet chamber I6 near the outer end of the case. A flanged sleeve I'I is tted in an opening in a hub in the side of the case opening into the mixing chamber, and a nipple I8 is extended loosely through said sleeve and to a point nearly flush with the inner wall of the chamber I5. This nipple is suitably formed for attachment thereto of a fuel supply tube, a lock nut I9 being employed to retain the nipple in place.

A fuel inlet tube 2D is screw threadedly engaged with the nipple I8, said tube having a fuel inlet passage 2| extending through the stem of the T- shaped part and into a fuel valve chamber 22 in the cross part of the T-shaped inlet tube. A fuel valve case 23 is screw threadedly engaged with one end of the cross part of the fuel inlet tube, the chamber in said case being substantially the size of the fuel Valve chamber 22.

An air valve 24 of a diameter slightly greater than the opening through the flange I4 is located within the chamber I I so that said valve will rest against a valve seat formed by said flange. A tubular valve stem 25 projects inwardly from the valve 24 and is slidingly fitted within a valve sleeve 26 integrally formed with a vacuum cup support 2l for a vacuum cup 28 opening downwardly and with its mouth surrounding the end of the fuel valve case 23. The sleeve 26 is slidably .mounted in an opening through a supporting bar 29 projecting across the chamber II and having supports 56 located in grooves on diametrically opposite sides of the shell I8 and rmly secured in place by the ilange I4 of the ring I3, as shown in Figures 4 and 9 of the drawing. When said ring is removed the bar 29 may be readily lifted out at the end of the shell. The outer section 30 of a fuel valve adjusting rod is slidably mounted at one end in a hub 3| projecting from the air valve 24, the inner end of said section being loosely engaged with one end of an inner section 32 of said rod, this engagement being such that turning movement of the outer section 3B will effect turning movement of the inner section 32. 'I'he outer end of the section 30 is suitably iormed to receive a wrench or other tool by means of which it may be turned. The section 32 is screw threadedly engaged through an opening in the vacuum cup support 21. An air valve spring 33 surrounds the fuel Valve adjusting rod within the opening in the valve stem 25, said spring thrusting at its lower end against the bottom of the recess in the vacuum cup support and at its opposite end against the bottom of the recess in the valvev stem 25, thereby exerting a pressure tending to close the air valve 24. This spring, however, is of such strength as to permit the air valve to readily open as may be required under conditions created within the chamber in the case.

An important feature of my invention resides in the construction of the fuel inlet valve which projects from the chamber in the valve case into a vacuum chamber 34 in the vacuum cup 28. This fuel valve 35 is preferably of solid cylindrical form, having a discharge notch 36 at its outer end, or that end located within the chamber 34, and a regulating groove 31 extending inwardly from said notch, said groove being of-a length to open into the fuel chamber 38 in the Valve case 23. The discharge notch is preferably cut through the end of the valve from side to side, and the regulating groove is tapered to produce a groove which is shallower at its inner end, or that end within the chamber 38, than at its opposite end which enters the notch 36. This fuel valve is preferably squared at itsropposite ends, that end within the chamber 34 seating against the threaded end of the inner section 32 of the valve adjusting rod, and the opposite end of the valve resting against a member 39 loosely mounted in the chamber 38 and resting against a spring 4l) located in said chamber.

The groove 31 is so arranged that its shallow end will be located just within the chamber 38 when the fuel valve 35 is in its closed position, thereby providing an opening just sufficient to admit fuel for idling purposes.

v This valve is very eifective and the arrangement of the tapered groove .presents a very minute opening suicient for idling purposes and such opening increases in size very slowly as compared with the lengthwise movement of the valve, thereby controlling admittance of fuel to the chamber 35 in a rnost effective manner to control the speed of a motor in connection with which the carburetor is used.

The fuel valve is operate-d by movement of the threaded section 32 of the fuel valve adjusting rod, the latter being operated by movement of the vacuum cup 23 effected by a lug 4l projecting from the vacuum cup and loosely engaged Within a slot in one arm 42 of a fuel valve operating lever, said lever also comprising an actuating arm 43 having means for connection with a manually operated member in a manner common to structures of this class, a further and detailed description-'being omitted herein as not necessary to an understanding of my invention. Said fuel valve operating leveralso includes a shaft rotatably mounted in the shell HJ and to the opposite ends of which said arms are rigidly attached, as shown in Figs. l, 2 and 5 of the drawing. A choke arm 44 comprisin.g;part of a choke lever is extended within the case in position to engage the airV valve 24 and prevent opening movement thereof, when such is desired, as in the operation of starting the motor. The: outer end 45 of said lever, located outside of the case, is connected for operation by means of a knob or other manually operated device conveniently located. This connection comprises a connecting Arod 46 having a recess extending inwardly from its outer end and into which an actuating rod 41 extends, the inner end of said rod having a head 48 to engage a block 49 secured within the outer end of said recess. An actuating collar 50 is adjustably secured to the rod 41, as by means of a set screw, as shown inFig. 8 of the drawing. A tensioning spring 5i is secured at one end tothe collar 5 and at its opposite end to the connecting rod 46. The end of the rod 41 is formed for connection with the manually actuated device hereinbefore referred to. Y

In the operation of this connection a pull upon the rod 41 causes the spring 5I to be extended, thereby placing a yielding restriction to opening movement of the valve 24 so that said Valve may open under the application of a sufficient amount of force. If it be desired to positively prevent opening movement of the air valve the rod 41 is extended until the head 48 encounters the block 49.

In carburetors heretofore employed it has beenv the practice, so far'as I am aware, to iix the closed position of the air inlet valve so that air is admitted for idling purposes, and in carburetors of the type herein shown and which I have invented I have provided a small hole through the valve 24 for such idling purposes. I have found that if this air valve is completely closed when starting an engine a material advantage will arise therefrom, and I have therefore provided means in the carburetor herein shown and described for effecting this result, the valve 24 being always open to a slight ldegree and sufliciently for idling purposes except during starting operation. To this end I extend, a fuel valve adjusting arm 52 from the fuel valve operating lever, and as shown in Figures l and 5 of the drawing, and thread a fuel valve adjusting screw 53 through said arm in positionto abut against a lug 54 pro` jecting from the side of the shell I0, and as shown in Figure l.v By adjusting this screw to the proper position they valve 24 will always be operi to a slight extent except during starting operation and when closed by the choke arm 44, and this same means correctly positions the fuel valve 35 so that the slot 31 will always be open suiciently for idling purposes.

In accordance with the provisions of the pat ent statutes Ihave described the principlesA of operation of my invention, together with the device which I now consider to represent the best embodiment thereof; but I desire to have it understood that the device shown is only illustrative,

`and that the invention may be carried out by other means and applied to uses other than those x above set out.

I claim:

1. In a carburetor including a shell Yhaving a Y ing in cross sectional area in the direction of flow of fluid along the valve, a springfor forcing the valve to its closed position, and means for moving the valve in opposition to said spring. V

2. In a carburetor including a shell having a fuel inlet and a valve casing vmember with a chamber therein, a valve smaller in size than said chamber and extending through the outlet from said chamber said Valve having a groove with an inclined bottom increasing the cross sectional area ofthe opening in' the direction of flow of fluid from said chamber, a valve engaging member loosely mounted in said chamber, and a spring seated against said valve engaging member for operation of said valve.

GRANT HAMMOND. 

